Can the 3D viewport be set to draw smooth (anti-aliased) wireframe?
I'm assuming you're talking about anti-aliasing:



This can be turned on in the User Preferences (found in the File menu), in the System tab:



You may need to click Save User Settings at the bottom left and restart Blender to see any effect.



Warning, on some systems (NVidia specifically) this can cause editmode vert/edge/face selection to fail. (This is an issue with the OpenGL driver and not much Blender can do to resolve)